Question

The distance to the andromeda galaxy is estimated at about 2 ´ 106 light years. a light year is the distance traveled by light in one year; if the speed of light is 3 ´ 108 m/s, about how far is it from our galaxy to andromeda? (1 year = 3.15 ´ 107 s)

Answer 1

The distance of andromeda to earth is, 2x10^6 light year.
Convert year to second by multiplying with 3.15x10^7.
Convert light second to meter by multiplying with 3x10^8.
So, the distance in meters is, 1.89x10^22 m.